The idea is simple. We need to get the siginfo for each signal on dump, and then return it back on restore.
The first problem is that the kernel doesn’t report complete siginfo-s in user-space. In a signal handler the kernel strips SI_CODE from siginfo. When a siginfo is received from signalfd, it has a different format with fixed sizes of fields. The interface of signalfd was extended. If a signalfd is created with the flag SFD_RAW, it returns siginfo in a raw format. We need to choose a queue, so two flags SFD_GROUP and SFD_PRIVATE were added. rt_sigqueueinfo looks suitable for restoring signals, but it can’t send siginfo with a positive si_code, because these codes are reserved for the kernel. In the real world each person has right to do anything with himself, so I think a process should able to send any siginfo to itself. Cc: Serge Hallyn <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: Al Viro <[email protected]> Cc: Pavel Emelyanov <[email protected]> CC: Cyrill Gorcunov <[email protected]> -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
